IPCC Working Group I (WGI) continued discussing line-by-line the Summary for Policy Makers (SPM) of the WGI report addressing the physical science basis of climate change. The document remains under embargo until it is fully finalized, and will be released on Friday morning, 27 September.

On Tuesday, in morning, afternoon and evening sessions, delegates discussed the section on observed changes in climate system, specifically in the atmosphere. Most time in the morning and afternoon was spent on two bullet points, on global temperature increase and on lower rates of warming in the last 15 years. The changes introduced by delegates to this text were mainly with the aim to communicate the underlying scientific explanation more clearly, accurately and in an accessible manner to policy makers. A number of informal consultation groups convened as well to discuss some of the more difficult issues in-depth.